Rubber covered roll and method of making same



l ,943. v. STOFFER 2,329,796

RUBBER COVERED ROLL AND METHOD OF MAKING SAME Filed Oct. 2, 1941 I 1-K II M I III JITEfi/ZZEL 0557"? L SZEJYEJL.

ipatented Sept. 23, L943 stares Virgil L; Stoifer, Akron, B. F. Goodrich Com Ohio, assignor to The pany, New York, N. Y, a

corporation of New York Application October 2, 1941, Serial No. 413,320

7 Claims.

This invention relates to the manufacture of rubber-covered rolls and is useful for example in the manufacture of wringer rolls.

Rubber-covered rolls heretofore have sometimes presented the difliculty that moisture com.- ing in contact with the end of the roll has tended to rust the shaft and loosen and separate the rubher from the shaft. The incorporation of protective bushings on the shaft at the ends of the'roll as practiced heretofore has not been entirely satisfactory owing to the lack of adequate attachment of the hard rubber bushings to the shaft, the bushings having been difficult to attach effectively to the shaft and having often moved along the shaft to an undesired position by the pressures upon them during molding of the roll.

The present invention aims to overcome these and other difficulties and to provide an improved article and method of procedure.

The principal objects of the invention are to provide a secure bond between the hard rubber bushing and the shaft, and .to provide against improper location of the bushings during the molding operation.

These and other objects will appear from the following description and the accompanying drawing.

Of the drawing:

Fig. 1 is a longitudinal sectional view of one end of a roll constructed in accordance with and embodying the invention.

Fig. 2 is a similar view of the parts of the roll assembled for molding.

Fig. 3 is a longitudinal section of the mold with the molded roll therein.

Fig. 4 is a view of the roll taken along the line i- 3 of Fig. 1.

In accordance with the invention, end bushings, incorporated with the roll during molding, are provided with tapered bores positioned to diverge from the shaft in the direction inwardly of the ends of the roll, so that softer rubber material of the roll body in the vicinity of the shaft is forced between the shaft and the bushings and adhered to both. At the ends of the roll the bushing fits close to or in contact with the shaft to act effectively as a guard. Hard rubber serves well as the material of the bushings, although I metal or other firm or hard substance, to which soft rubber can be strongly adhered may be used.

In practicing the invention the following illustrative procedure may be followed. A pair of bushings, preferably molded and semicured from hard rubber composition, are cleaned and cemented, the shaft is prepared as by electroplatpressed thereabout to mold the article.

ing it with brass for adhesion, a layer of tie or soft adhesive sheet rubber of substantial tness is applied about substantially the length m. the shaft to be covered to provide a layer of soft bonding material of substantial thickness, preferably however not exceeding the largest bore of the bushings, while partially occupying the space between the bore of the bushings and the shaft. the hard rubber bushings are placed over ends of the rubber material about the shaft, bular body of rubber suitable for the cusl placed over the covered shaft and the inner of the bushings, and confining mold members a viding the tapered bore in thebushiugs readily forced over the rubber mate 1 covering on the shaft which material fills tapered space and provides a secure bond T the shaft. By tapering the outside'o'f the bus ings, the bushings are forced to the mold cavity during molding so that they wil positioned at the end faces of the roll.

Referring to the drawing, the numeral it designates a steel shaft of a wringer roll, about which is a cushion body Moi-soft vulcanized rubber. Hard rubber bush'mgs: .82 are embedded in ends of the roll aboutthe shaft to prevent cor rosion of the shaft and deterioration of the roll body by contact with oil and grease. A layer of tie-gurn or soft adhesive rubber of substan thickness as shown adapted to provide a between the rubber cushion'and bushings metal shaft extends over the shaft and the bushings. To provide for flow of the layer l3 between the bushings and the shaft, the ing is provided with a tapered bore i i of grea diameter toward the middle of the roll, an provide for forcing of the bushings to the during the molding operation the bosl'iings formed with inwardly facing shoulders l5, erably tapered to present a broad surface pa pen-dicular to the direction of flow which is a r sultant of forces applied radially and axially the shaft.

In manufacturing the roll, the shaft is prepared for bonding it to the rubber, p aby electroplating the shaft with a zines thes .Shaft, bushings 0f rubber composition and semicured. These are then cleaned, preferably by blasting them with steel shot, and are then coated inside and out with rubber cement and dried. ,The bushings are formed with a tapered bor'e larger at the innermost end than the shaft. They are forced over the shaft and over the ends of the tie-gum layer l3 to a position where they are only slightly further apart than in their final positions.

The rubber material for the cushion body is extruded to provide a tube 20 shorter than the desired covering and having a bore 2| larger than the largest diameter of the hard rubber bushings, and is compressed thereabout in a mold having a pair of mold plates 22, 23 defining therebetween a cylindrical cavity 24 of the desired roll diameter and slightly larger than the length of the desired roll body. The mold plates are also formed with half round grooves 25, 26 for centering the shaft. ing a bore adapted to slip over perimeter beveled as at 29 to assist in assembling the mold and of the same diameteras the roll cavity in the mold, are slipped over the ends of the shaft before the roll parts are placed .in

the mold.

As the roll body material is shorter than the body of the finished roll, the material flows 'toward the ends of the mold cavity as the moldzis closed and the pressure against the shoulders of the bushings holds them in proper position. The tie-gum is forced between the hard rubber bushings and the shaft providing a good bond'there- :between. The rubber of the'bodybecomesvul- "canized in the mold'by and pressure thereto.

'For increasing the strength of the union between the body and the-bushings, the bushings may be provided with corrugations 30 on their outer surfaces.

Variations may be made without departing from the scope of the invention as it is-defined by the following claims.

I claim:

1. A rubber-covered roll comprising a metal shaft, a body of soft rubber materialupon the harder material embedded in said body at the ends of the roll, said bushings having enlarged bores at their inwardly facing ends spacing them from the shaft throughout at least a part-of their extent, and a bodyof soft rubber bonding'material'of substantial thickness between said shaft and each of said bushings;

A pair of metal discs 21, 28 havthe shaft and a the application of :heat 1:

2. A rubber-covered roll comprising a metal shaft, a. body of soft rubber material upon the shaft, and bushings of hard rubber material embedded in said body atthe ends of the roll, said bushings having enlarged bores at their inwardly facing ends spacing them from said shaft, said fin-said body at the ends of the roll, said bushings having tapered bores substantially equal in diam- 17; etertothe'shaft at their outer faces and having soft rubber material in the bores.

4. A rubber-covered roll comprising a metal shaft, a. of soft rubber material upon the shaft and bushings of hard rubber material embedded in said body at the ends of the roll, said bushings having-tapered bores substantially equal 'in'diameter to said shaft at their outer facesand having their bores filled with soft rubber mmrial adhered to the shaft and bushings.

5. A method of making a rubber-covered roll which comprises winding about .a shafts. layer of sheet rubber materiaL-placing a pair of subber bushingspartially-over-the endsofrsaid layer, and molding a body of cushion sheet aubber material upon saidbushings and iayenwhile :molding the rubber material also in the horemif aid bushings.

6. The method of making-.a-rubber cnveredaoll which compriseszapplying -.to a shaft players! rubber material, rplacing a :pair of rubber bushings having tapered --bcres partially :over :said layer, and molding n body'ofzcmhionrubberzupon .said bimhings amid llayer while :molding :the rubber material also iinthe bore-ofteaidbushings.

7. The method nfzmaking .a :rubher-ecoverediroll which comprises covering a-xhaftwith unvulm ized rubber compositmnrplacinga pair of'imsbings of semicured hard rubber having tapered bores over the ends of said covering, :placingm. cylindrical body of rubber compnsttionabout said bushings and said coverlng andrmolding thembber composition about said bushings andisald covering and in the tapered bures-ofsaid bushings.

men-1L. STQFFER. 

